It is known to provide a spirit-level-type clinometer which is clampable to the side of a pipe for gauging bending or rotation of the pipe, e.g. U.S. patent to Traupmann No. 2,824,381. Said patent discloses a clamp comprising a V-shaped seat, and a co-operating hook pulled toward the seat by a hand-wheel threadedly engaged with the shank of the hook. It is accordingly the principal object of this invention to provide a pipe-bend-gauging dial-type clinometer which can be (one-handedly) very quickly and easily and securely clamped axially or transaxially to the rim of a pipe end. Other objects and advantages will become apparent as the following detailed description proceeds.